CA1218360A - Separation of gluten and starch from wheat flour - Google Patents
Separation of gluten and starch from wheat flourInfo
- Publication number
- CA1218360A CA1218360A CA000423962A CA423962A CA1218360A CA 1218360 A CA1218360 A CA 1218360A CA 000423962 A CA000423962 A CA 000423962A CA 423962 A CA423962 A CA 423962A CA 1218360 A CA1218360 A CA 1218360A
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- starch
- fraction
- section
- hydrocyclone
- gluten
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
- C08B30/00—Preparation of starch, degraded or non-chemically modified starch, amylose, or amylopectin
- C08B30/04—Extraction or purification
- C08B30/042—Extraction or purification from cereals or grains
- C08B30/046—Extraction or purification from cereals or grains from wheat
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- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
- Noodles (AREA)
- Cereal-Derived Products (AREA)
- Steroid Compounds (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
- Saccharide Compounds (AREA)
- Paper (AREA)
Abstract
ABSTRACT
SEPARATION OF GLUTEN AND STARCH FROM WHEAT FLOUR
In a process utilising a battery of hydrocyclones for separating wheat starch and gluten contained in an aqueous wheat flour slurry, the slurry is supplied to a first section of the hydrocyclone battery, in which a gluten fraction is removed as overflow, and the starch-rich fraction from such first battery section is first treated to reduce its pentosan content and is then treated in a second section of the hydrocyclone battery which delivers a concentrated starch fraction as underflow.
SEPARATION OF GLUTEN AND STARCH FROM WHEAT FLOUR
In a process utilising a battery of hydrocyclones for separating wheat starch and gluten contained in an aqueous wheat flour slurry, the slurry is supplied to a first section of the hydrocyclone battery, in which a gluten fraction is removed as overflow, and the starch-rich fraction from such first battery section is first treated to reduce its pentosan content and is then treated in a second section of the hydrocyclone battery which delivers a concentrated starch fraction as underflow.
Description
~L2~336~) Sl.I'ARATION Ol` GLUTEI~ ~ND STARCII FRO~I W~IEAT FLOUR
".,._, ~
This inver-~tion rela-tes to a proeess For separat;ng wheat s-tareh and cJluten, eontainecl in an aqueous wheat flour slurry, by means of hyc~roeye:Lones.
A hyclroeyelorle, as is well ~nown eomprises a 5 radial.!.y symmel:r:ieal ehamber, herei.rl eal:Led "vortex ehamber;', whieh tapers over the whole or tllc greatcr part of its len(Jth ancl has a feecd passage openillg into ;ts wider end, and opposed ax:ial diseharge apertures. ~Vhen l.iquid i.s Fed eontinuously under pressure through the feecl 10 passaye, the :Liquid forms in the ehamber a vortex wherein the anc~ular vcloeity increases from the inner surfaee t ,!'`~ ~ of the ehamber towards the vortex eore and Liquicd eontinuously (I:iseharges from the ehamber throuyll i.ts opposed axial di.seharge apertures. ~hen solid partieles are 15 entrained in the liquicl their movenrerlt in the vor-tex ehalllber is (~overned by eentrifugal and eentripe-tal forees and they may leave the hydroeyelone through thc disehar(~e aperture in .its wider erlcl~ or through its apex disehar~e apcrture, depellcl.ing on thc~ s-~ttlillg ratc- of the partielcs 20 in a stat:ie b()cly of the l;quid. Hy(lroeyelolles have bcen used very sueec~ssful]y ror several deel(.les as a tool for separa-tin(J partieles of different eomposi-t;.ons into fraet;ons of partieles of d.ifferellt settl:iny rates.
Y;i'~9' ~2~8~C)
".,._, ~
This inver-~tion rela-tes to a proeess For separat;ng wheat s-tareh and cJluten, eontainecl in an aqueous wheat flour slurry, by means of hyc~roeye:Lones.
A hyclroeyelorle, as is well ~nown eomprises a 5 radial.!.y symmel:r:ieal ehamber, herei.rl eal:Led "vortex ehamber;', whieh tapers over the whole or tllc greatcr part of its len(Jth ancl has a feecd passage openillg into ;ts wider end, and opposed ax:ial diseharge apertures. ~Vhen l.iquid i.s Fed eontinuously under pressure through the feecl 10 passaye, the :Liquid forms in the ehamber a vortex wherein the anc~ular vcloeity increases from the inner surfaee t ,!'`~ ~ of the ehamber towards the vortex eore and Liquicd eontinuously (I:iseharges from the ehamber throuyll i.ts opposed axial di.seharge apertures. ~hen solid partieles are 15 entrained in the liquicl their movenrerlt in the vor-tex ehalllber is (~overned by eentrifugal and eentripe-tal forees and they may leave the hydroeyelone through thc disehar(~e aperture in .its wider erlcl~ or through its apex disehar~e apcrture, depellcl.ing on thc~ s-~ttlillg ratc- of the partielcs 20 in a stat:ie b()cly of the l;quid. Hy(lroeyelolles have bcen used very sueec~ssful]y ror several deel(.les as a tool for separa-tin(J partieles of different eomposi-t;.ons into fraet;ons of partieles of d.ifferellt settl:iny rates.
Y;i'~9' ~2~8~C)
2.
Hydrocyclones have been used extensively in the starch industry for severa] decades in the recovery oE starch f~om maize. This use of hydrocyclone is described, e.g., in ~nited States Patent No 2 68g ~10. The starch slurry is passed through a succession of hydrocyclone stages in counter current with wash water. Each said stage comprises a multiplicity of hydrocyclones operating in parallel. By using hydrocyclones in this way it is possible to obtain a dense suspension of clean starch, representing a high percentage of the total starch in the feed stream, as the apex discharge fraction (the so-called "under10w" fraction) from the hydrocyclones.
It has been proposed, see e.g. United States Patent 4 132 566 and United Kingdom Patent ~pplication 2 032 245 ~published on 8th May 1980) to use hydrocyclones in the processing of a wheat flour slurry.
The use of hydrocyclones for separating wheat starch and gluten has the advantage as compared with other known methods, that it requires much less water per unit quantity oE flour, and consequently less energy is required for evaporating contaminated water and keeping the sewage volume within acceptable limits. Moreover the high shearing Eorces generated within the hydrocyclones pre-condition the gluten in a way which promotes its separation so that a high yield of high quality gluten or, what is more important, of its insoluble protein constituent, is obtained, also from soft wheat Elour. However the previously proposed processes for separately recovering wheat starch and gluten from a wheat flour slurry by using hydrocyclone~ suffer from the disadvantage that the yield of prime starch is lower than that which might reasonably be expected.
tluch resedrch has b~ell under-taken into the causes of the .I.ower e-Ffectiveness o-F hydrocyclorles -for halldling wheat F:lour slurries, with a view to overcoming this problem. A possibl.e contributory factor was recogrlised 5 in the peculi.ar particle sizc-~ distribu-tion of the starch constituellt of the wlleat. \~'heat starch particles are typically distributed over distinct particlc size ranyes, such as approximately 2 to 8 microns ancd approximately 12 to 40 microns. But experiments showe(l 10 that the cause or the principal cause of the limited separatirlg ef`Ficiency has to bc found e:Lsewhere.
The present invention is based on ttle discovery that f;bre and pentosans, when present in the feed s-tream to a hydrocyclone, adversely affect the operation of the 15 hydrocyclorle. The adverse efFect seems to be a-ttri.butable to an influence which the fibre and pentosans, particularly the latter, haYe on the viscosity of the slurry when they are subfected to the shear -forces which prevail in the liquid vortex. An increase 20 in the viscosity of -the liquid in a hydrcyclone reduces its effici.ency by redueing the propor-tion of the feed , .....
} stream energy which is transla-ted into kinetic energy of rotation near the core of the vortex, whiell latter energy should be as high as possible For achieving 25 maximum separating efficiency, particularly in respect of very small particles.
The aForesaid adverse eFFect becomes more serious because at tlle present t.ime it is neccssary f`or wheat starch plants to reduce t:heir water consumption in 30 order to reduce or e:Liminate process water sewage disposal or evaporatiorl costs. The less the amount of water passin(J -through thc sys-tem, thc h:igller is the pentosan concentra-ti.on.
~836'QI
4.
The process according to the present invention involves the use of hydrocyclone apparatus split into two sections for perforrning different separating operations and the removal sf pentosans or oE fibre and pentosans between those operations.
~ process according to the invention is defined in claim 1 hereof. The process is characterised in that the aqueous flour slurry is fed into a first section of a hydrocyclone apparatus which delivers a starch-rich underflow fraction, and an overflow fraction containing the gluten and some starch;
agglomerated gluten is removed from said overflow fraction by screening; the starch-containing throughput from this screening operation and the underflow fraction from said first section of the hydrocyclone apparatus are centrifuged thereby to separate off a pentosan-containing water fraction as centrifuge overflow; and the centrifuge underflow is fed into a second section of the hydrocyclone apparatus, in which second section the starch is washed in counter-current with water and from which a concentrated washed starch fraction is delivered as the underflow.
~0 In this process, the hydrocyclones constituing the ~irst section have merely to effect a rough separation to remove gluten from the flour slurry. For the purpose of this rough separation, the effect of pentosans in the slurry is relatively unimportant. The gluten becomes subjected in these hydrocyclones, which can conveniently be called "the gluten cyclones", to shearing forces which affect the gluten in ways which predispose it to agglomeration into larger quanta in the form o~ lumps or threads. In addition, the shear forces have the effect of releasing gluten-bound starch.
The first hydrocyclone section may comprise for example from two to six hydrocyclone stages connected in series.
It is an advan~age to feed these hydrocyclones under a relatively high pressure in order to generate high shear forces for pre-conditioning the gluten. Prior to being fed into the gluten hydrocyclones the flour slurry can be subjected to shear forces by kneading or agitation or otherwise as known per se in the wheat starch industry in order to promote hydration and development of the gluten, thereby further facilitating its subsequent removal.
The agglomerated gluten can be removed from the overflow fraction from the gluten cyclones by means of screens (hereafter called "gluten screens"), and the throughput from these screens can than be added to the starchy underflow fraction from the gluten cyclones prior to treatment thereof to remove pentosans.
For achieving the best results. the pentosans should be lS removed as completely as possible from the slurry to be fed to the second section of the hydrocyclone apparatus. However, it is not necessary to effect subs~antially complete re~oval of the pentosans in order to achieve a significant improvement ln the starch yield. The pentosans have a marked affinity for water and at least the greater part of the pentosan content of the slurry can be removed by removing the greater part of the water therefrom by means of the centrifuge. The operation of a centriEuge is not dependent on the viscosity of the feedstock in the same way as a hydrocyclone. By means of a centrifuge pentosans are quickly removed and discharged together with an amount of water and soluble impurities as the centrifuge overflow. The overflow can be recycled in the plant for use as process water. e.g. in the flour and water ~2~8~3~,0 6.
mixing and kneading station, any surplus being evaporated.
The extent of water removal by the centrifuge can be such as to bring the starch slurry to an appropriate density for feeding into the second stage of the hydrocyclone apparatus.
~s previously indicated, a further discovery during research leading up to the present invention is that the presence of fibre, particularly fibre of about 150 to 200 microns in si~e, in the feedstream to the hydrocyclones of the second section of the hydrocyclone apparatus ~which can conveniently be called "the refining cyclones") can also adversely affect their separating efficiency. and although an improvement in the starch yield can be achieved without removing fibre or without removing any appreciable amount of fibre from the slurry feeding to those cyclones, it is desirable to include a fibre removal step in order to ma~e the starch yield as high as possible. A large percentage of ~he fibre can be removed by screening at least part of the slurry which forms the underflow from the gluten cyclones. The screen or set of screens used Eor screening off fibre may also remove some pentosans ~0 (pentosans bound to the fibre).
The second section oE the hydrocyclone apparatus, which comprise~ the reEining cyclones, may comprise, for example from six to twelve hydrocyclone stages. In this battery the starch is washed in counter-current with wash water in order to remove most of the residual soluble and non-soluble contaminants.
The splitting of the hydrocyclone apparatus and the removal of pentosans or pentosans and fibre from the slurry prior to treatment in the refining cyclones affords important advantages because of the higher separating efficiency of these cyclones.
~:1836~
7.
The higher efficiency of the refining hydrocyclones means ~hat an appreciably larger amount of prime (A-grade) wheat starch can be recovered for given fresh water and energy consumption values. Tes~s indicate that by using a process according to the invention and in which at least the gr-eater part of the pentosans and of the fibre are removed between the treatments in the first and second hydrocyclone sections, wheat starch recovery, expressed as a percentage of the wheat flour weight, can be considerably higher than the best recovery hitherto achieved by means of hydrocyclones, with comparable process conditions and fresh water consumption. The higher starch recovery is particularly evident in the case of the wheat starch particles in the lower size range, below 10 microns.
~nother important advantage is the fact that at the same time the process is capable of giving a high yield of insoluble protein, this being the valuable major constituent of the separated gluten fraction.
The process according to the invention is applicable for processing hard and soft wheat flour, including wholemeal flour. Its usefulness for processing soft wheat flour is partlcularly valuable because gluten separation from soft wheat flour normally involves more difficulty.
The invention includes apparatus for use in separating wheat starch and gluten present in a pentosan-containing wheat flour slurry by a process according to the invention as hereinbefore defined. Such apparatus according to the invention is defined in claim 4 hereof.
An embodiment of the invention will now be described by way of example with reference to the accompanying flow sheet representing a wheat starch recovery plant.
In station 1, water and wheat flour are mixed and kneaded and/or stirred in ways known to those skilled lZ183~i0 in the art. Tlle resul-ting slurry is pumped into the first section 2 oF a hydrocyclolle battery, which section effec-ts separation of the slurry i.nto a starch-rich -fraction wh;.ch discharges as underflow, and an overflow 5 frac-tion whicll includes the gluten and some s-tarch.
Tllis overflow fraction is screened irl a screening station 3. In consequence of the repea-~ed shearing .actions on the slurry, especially in the hydrocyclones, -the glu-ten becomes agglomerated and can be screened off 10 ~on screens ~Yi th openings of 0.3 - 2 mm width. The slurry passing through the screens is ac!ded -to the under-flow of the -first hyclrocyclone battery section 2 and screened in a screening station 4, in which part of the pen-tosans arld -the -fibre are caugllt on screens with 50 - 150 micron 15 openings~ and uasllecl -free From starch. The filtrate From screening sta-tion 4 is then -fecl to a centrifugal separator 5 in which mos-t of the remaining pentosans, whicrl had marked afFinity for water, are removecl in -the overflow "vhich is available for use as process water in 20 different sect;ons of the plant. Centri.fuge 5, being a f mecllallical separator, is much less vulnerable tharl llydrocyclones to increases in viscosity and is well able to concen-trate substantially a]l o-f the s-tarch particles in its underflow. Screens 4 and centrifuge 5 are 25 interposed between the first section 2 and tlle second section 6 of the hydrocyclones bat-tery, whicll second seCtiOrl comprises d series oF 6 12 multihydrocyclone stages i.n wllicl-l the starch is washed with fresh water countercurrently, to remove residual solubles and 30 insoluble contaminants an(l deliver a prime or so-called A-grade starch sl.urry.
33~0 The overflow from station 6 is fed -to a concen-trating and dewatering station 7 for B-grade starch. The overflow from this sta-tion 7 is also available for use as process water in different sections of the plant; excess process water is evaporated in evaporator 8. The concentra-te of the evaporator comprises minerals, pentosans and some liqllefied s-tarch. The quantity of process water tha-t has to be evaporated to avoid any discharge of water to the sewer is no-t more than one and a half times the weight of flour.
The described system can be varied in severa]
ways without seriously affecting overall performance, as :Long as the hydrocyclone ba-ttery is split up into two sections and a pentosan reducing facili-ty is interposed between -the two sections.
The wa-ter temperature is preferably held in the range 30 to 45 C in the whole process.
Example Using the described system according to the invention, for recovering starch and gluten from soft wheat flour the following yields were obtained for a fresh water consurnption of 2.2 m3/ton of flour:
Yield Insoluble protein(based on the insoluble protein content of the flour) 94 %
A-grade starch (based on 59 %
dry solids) B--yrade starch (based on dry solids) l7 %
121~6~
io --By cornpa:rison,when performing -the process without removing pentosans or fibre i-t was found that e~en when increasing the fresh water consumpti.on to 4 m3/ton of -the flour, 1he insoluble ~rotein yield was only R8% and the yield of A-grade starch was only 54%; whereas the yield oE B-grade starch was 19%.
This high wa-ter consumption could be considerably reduced by removing only pentosans but the separating efficiency wo~ld not be so high as in the above 1.0 Example.
Hydrocyclones have been used extensively in the starch industry for severa] decades in the recovery oE starch f~om maize. This use of hydrocyclone is described, e.g., in ~nited States Patent No 2 68g ~10. The starch slurry is passed through a succession of hydrocyclone stages in counter current with wash water. Each said stage comprises a multiplicity of hydrocyclones operating in parallel. By using hydrocyclones in this way it is possible to obtain a dense suspension of clean starch, representing a high percentage of the total starch in the feed stream, as the apex discharge fraction (the so-called "under10w" fraction) from the hydrocyclones.
It has been proposed, see e.g. United States Patent 4 132 566 and United Kingdom Patent ~pplication 2 032 245 ~published on 8th May 1980) to use hydrocyclones in the processing of a wheat flour slurry.
The use of hydrocyclones for separating wheat starch and gluten has the advantage as compared with other known methods, that it requires much less water per unit quantity oE flour, and consequently less energy is required for evaporating contaminated water and keeping the sewage volume within acceptable limits. Moreover the high shearing Eorces generated within the hydrocyclones pre-condition the gluten in a way which promotes its separation so that a high yield of high quality gluten or, what is more important, of its insoluble protein constituent, is obtained, also from soft wheat Elour. However the previously proposed processes for separately recovering wheat starch and gluten from a wheat flour slurry by using hydrocyclone~ suffer from the disadvantage that the yield of prime starch is lower than that which might reasonably be expected.
tluch resedrch has b~ell under-taken into the causes of the .I.ower e-Ffectiveness o-F hydrocyclorles -for halldling wheat F:lour slurries, with a view to overcoming this problem. A possibl.e contributory factor was recogrlised 5 in the peculi.ar particle sizc-~ distribu-tion of the starch constituellt of the wlleat. \~'heat starch particles are typically distributed over distinct particlc size ranyes, such as approximately 2 to 8 microns ancd approximately 12 to 40 microns. But experiments showe(l 10 that the cause or the principal cause of the limited separatirlg ef`Ficiency has to bc found e:Lsewhere.
The present invention is based on ttle discovery that f;bre and pentosans, when present in the feed s-tream to a hydrocyclone, adversely affect the operation of the 15 hydrocyclorle. The adverse efFect seems to be a-ttri.butable to an influence which the fibre and pentosans, particularly the latter, haYe on the viscosity of the slurry when they are subfected to the shear -forces which prevail in the liquid vortex. An increase 20 in the viscosity of -the liquid in a hydrcyclone reduces its effici.ency by redueing the propor-tion of the feed , .....
} stream energy which is transla-ted into kinetic energy of rotation near the core of the vortex, whiell latter energy should be as high as possible For achieving 25 maximum separating efficiency, particularly in respect of very small particles.
The aForesaid adverse eFFect becomes more serious because at tlle present t.ime it is neccssary f`or wheat starch plants to reduce t:heir water consumption in 30 order to reduce or e:Liminate process water sewage disposal or evaporatiorl costs. The less the amount of water passin(J -through thc sys-tem, thc h:igller is the pentosan concentra-ti.on.
~836'QI
4.
The process according to the present invention involves the use of hydrocyclone apparatus split into two sections for perforrning different separating operations and the removal sf pentosans or oE fibre and pentosans between those operations.
~ process according to the invention is defined in claim 1 hereof. The process is characterised in that the aqueous flour slurry is fed into a first section of a hydrocyclone apparatus which delivers a starch-rich underflow fraction, and an overflow fraction containing the gluten and some starch;
agglomerated gluten is removed from said overflow fraction by screening; the starch-containing throughput from this screening operation and the underflow fraction from said first section of the hydrocyclone apparatus are centrifuged thereby to separate off a pentosan-containing water fraction as centrifuge overflow; and the centrifuge underflow is fed into a second section of the hydrocyclone apparatus, in which second section the starch is washed in counter-current with water and from which a concentrated washed starch fraction is delivered as the underflow.
~0 In this process, the hydrocyclones constituing the ~irst section have merely to effect a rough separation to remove gluten from the flour slurry. For the purpose of this rough separation, the effect of pentosans in the slurry is relatively unimportant. The gluten becomes subjected in these hydrocyclones, which can conveniently be called "the gluten cyclones", to shearing forces which affect the gluten in ways which predispose it to agglomeration into larger quanta in the form o~ lumps or threads. In addition, the shear forces have the effect of releasing gluten-bound starch.
The first hydrocyclone section may comprise for example from two to six hydrocyclone stages connected in series.
It is an advan~age to feed these hydrocyclones under a relatively high pressure in order to generate high shear forces for pre-conditioning the gluten. Prior to being fed into the gluten hydrocyclones the flour slurry can be subjected to shear forces by kneading or agitation or otherwise as known per se in the wheat starch industry in order to promote hydration and development of the gluten, thereby further facilitating its subsequent removal.
The agglomerated gluten can be removed from the overflow fraction from the gluten cyclones by means of screens (hereafter called "gluten screens"), and the throughput from these screens can than be added to the starchy underflow fraction from the gluten cyclones prior to treatment thereof to remove pentosans.
For achieving the best results. the pentosans should be lS removed as completely as possible from the slurry to be fed to the second section of the hydrocyclone apparatus. However, it is not necessary to effect subs~antially complete re~oval of the pentosans in order to achieve a significant improvement ln the starch yield. The pentosans have a marked affinity for water and at least the greater part of the pentosan content of the slurry can be removed by removing the greater part of the water therefrom by means of the centrifuge. The operation of a centriEuge is not dependent on the viscosity of the feedstock in the same way as a hydrocyclone. By means of a centrifuge pentosans are quickly removed and discharged together with an amount of water and soluble impurities as the centrifuge overflow. The overflow can be recycled in the plant for use as process water. e.g. in the flour and water ~2~8~3~,0 6.
mixing and kneading station, any surplus being evaporated.
The extent of water removal by the centrifuge can be such as to bring the starch slurry to an appropriate density for feeding into the second stage of the hydrocyclone apparatus.
~s previously indicated, a further discovery during research leading up to the present invention is that the presence of fibre, particularly fibre of about 150 to 200 microns in si~e, in the feedstream to the hydrocyclones of the second section of the hydrocyclone apparatus ~which can conveniently be called "the refining cyclones") can also adversely affect their separating efficiency. and although an improvement in the starch yield can be achieved without removing fibre or without removing any appreciable amount of fibre from the slurry feeding to those cyclones, it is desirable to include a fibre removal step in order to ma~e the starch yield as high as possible. A large percentage of ~he fibre can be removed by screening at least part of the slurry which forms the underflow from the gluten cyclones. The screen or set of screens used Eor screening off fibre may also remove some pentosans ~0 (pentosans bound to the fibre).
The second section oE the hydrocyclone apparatus, which comprise~ the reEining cyclones, may comprise, for example from six to twelve hydrocyclone stages. In this battery the starch is washed in counter-current with wash water in order to remove most of the residual soluble and non-soluble contaminants.
The splitting of the hydrocyclone apparatus and the removal of pentosans or pentosans and fibre from the slurry prior to treatment in the refining cyclones affords important advantages because of the higher separating efficiency of these cyclones.
~:1836~
7.
The higher efficiency of the refining hydrocyclones means ~hat an appreciably larger amount of prime (A-grade) wheat starch can be recovered for given fresh water and energy consumption values. Tes~s indicate that by using a process according to the invention and in which at least the gr-eater part of the pentosans and of the fibre are removed between the treatments in the first and second hydrocyclone sections, wheat starch recovery, expressed as a percentage of the wheat flour weight, can be considerably higher than the best recovery hitherto achieved by means of hydrocyclones, with comparable process conditions and fresh water consumption. The higher starch recovery is particularly evident in the case of the wheat starch particles in the lower size range, below 10 microns.
~nother important advantage is the fact that at the same time the process is capable of giving a high yield of insoluble protein, this being the valuable major constituent of the separated gluten fraction.
The process according to the invention is applicable for processing hard and soft wheat flour, including wholemeal flour. Its usefulness for processing soft wheat flour is partlcularly valuable because gluten separation from soft wheat flour normally involves more difficulty.
The invention includes apparatus for use in separating wheat starch and gluten present in a pentosan-containing wheat flour slurry by a process according to the invention as hereinbefore defined. Such apparatus according to the invention is defined in claim 4 hereof.
An embodiment of the invention will now be described by way of example with reference to the accompanying flow sheet representing a wheat starch recovery plant.
In station 1, water and wheat flour are mixed and kneaded and/or stirred in ways known to those skilled lZ183~i0 in the art. Tlle resul-ting slurry is pumped into the first section 2 oF a hydrocyclolle battery, which section effec-ts separation of the slurry i.nto a starch-rich -fraction wh;.ch discharges as underflow, and an overflow 5 frac-tion whicll includes the gluten and some s-tarch.
Tllis overflow fraction is screened irl a screening station 3. In consequence of the repea-~ed shearing .actions on the slurry, especially in the hydrocyclones, -the glu-ten becomes agglomerated and can be screened off 10 ~on screens ~Yi th openings of 0.3 - 2 mm width. The slurry passing through the screens is ac!ded -to the under-flow of the -first hyclrocyclone battery section 2 and screened in a screening station 4, in which part of the pen-tosans arld -the -fibre are caugllt on screens with 50 - 150 micron 15 openings~ and uasllecl -free From starch. The filtrate From screening sta-tion 4 is then -fecl to a centrifugal separator 5 in which mos-t of the remaining pentosans, whicrl had marked afFinity for water, are removecl in -the overflow "vhich is available for use as process water in 20 different sect;ons of the plant. Centri.fuge 5, being a f mecllallical separator, is much less vulnerable tharl llydrocyclones to increases in viscosity and is well able to concen-trate substantially a]l o-f the s-tarch particles in its underflow. Screens 4 and centrifuge 5 are 25 interposed between the first section 2 and tlle second section 6 of the hydrocyclones bat-tery, whicll second seCtiOrl comprises d series oF 6 12 multihydrocyclone stages i.n wllicl-l the starch is washed with fresh water countercurrently, to remove residual solubles and 30 insoluble contaminants an(l deliver a prime or so-called A-grade starch sl.urry.
33~0 The overflow from station 6 is fed -to a concen-trating and dewatering station 7 for B-grade starch. The overflow from this sta-tion 7 is also available for use as process water in different sections of the plant; excess process water is evaporated in evaporator 8. The concentra-te of the evaporator comprises minerals, pentosans and some liqllefied s-tarch. The quantity of process water tha-t has to be evaporated to avoid any discharge of water to the sewer is no-t more than one and a half times the weight of flour.
The described system can be varied in severa]
ways without seriously affecting overall performance, as :Long as the hydrocyclone ba-ttery is split up into two sections and a pentosan reducing facili-ty is interposed between -the two sections.
The wa-ter temperature is preferably held in the range 30 to 45 C in the whole process.
Example Using the described system according to the invention, for recovering starch and gluten from soft wheat flour the following yields were obtained for a fresh water consurnption of 2.2 m3/ton of flour:
Yield Insoluble protein(based on the insoluble protein content of the flour) 94 %
A-grade starch (based on 59 %
dry solids) B--yrade starch (based on dry solids) l7 %
121~6~
io --By cornpa:rison,when performing -the process without removing pentosans or fibre i-t was found that e~en when increasing the fresh water consumpti.on to 4 m3/ton of -the flour, 1he insoluble ~rotein yield was only R8% and the yield of A-grade starch was only 54%; whereas the yield oE B-grade starch was 19%.
This high wa-ter consumption could be considerably reduced by removing only pentosans but the separating efficiency wo~ld not be so high as in the above 1.0 Example.
Claims (5)
The embodiments of the invention, in which an exclusive privilage or property is claimed, are defined as follows:
1. A process for separating wheat starch and gluten, present in a pentosan-containing aqueous wheat flour slurry, which process comprises the steps of feeding said aqueous flour slurry into a first section of a hydrocyclone apparatus which delivers a starch rich underflow fraction and an overflow fraction containing gluten and some starch;
removing agglomerated gluten from said overflow fraction by screening;
centrifuging the starch-containing throughput from this screening operation and the underflow fraction from said first section of the hydrocyclone apparatus thereby to separate off a pentosan-containing water fraction as centrifuge overflow; and feeding the centrifuge underflow into a second section of the hydrocyclone apparatus in which second section starch is washed in counter-current with water and from which a concentrated washed starch fraction is delivered as underflow, whereby the separation of the pentosan-containing water fraction improves the yield of starch from the second section of the hydrocyclone apparatus.
removing agglomerated gluten from said overflow fraction by screening;
centrifuging the starch-containing throughput from this screening operation and the underflow fraction from said first section of the hydrocyclone apparatus thereby to separate off a pentosan-containing water fraction as centrifuge overflow; and feeding the centrifuge underflow into a second section of the hydrocyclone apparatus in which second section starch is washed in counter-current with water and from which a concentrated washed starch fraction is delivered as underflow, whereby the separation of the pentosan-containing water fraction improves the yield of starch from the second section of the hydrocyclone apparatus.
2. A process according to claim 1, wherein at least the underflow fraction from the first hydrocyclone section is screened to remove fibre.
3. A process for separating wheat starch and gluten, present in a pentosan-containing aqueous wheat flour slurry, which process comprises the steps of feeding said aqueous flour slurry into a first section of a hydrocyclone apparatus which delivers a starch-rich underflow fraction, and an overflow fraction containing gluten and some starch;
removing agglomerated gluten from said overflow fraction by a screening operation; subjecting the starch-containing throughput from that screening operation and the underflow fraction from said first section of the hydrocyclone apparatus first to a screening treatment to reduce their fiber content and then to centrifuging, thereby to separate off a 12.
pentosan-containing water fraction as centrifuge overflow; and feeding the centrifuge underflow into a second section of the hydrocyclone apparatus in which second section the starch is washed in counter-current with water and from which a concentrated washed starch fraction is delivered as underflow, whereby the separation of the pentosan-containing water fraction improves the yield of starch from the second section of the hydrocyclone apparatus.
removing agglomerated gluten from said overflow fraction by a screening operation; subjecting the starch-containing throughput from that screening operation and the underflow fraction from said first section of the hydrocyclone apparatus first to a screening treatment to reduce their fiber content and then to centrifuging, thereby to separate off a 12.
pentosan-containing water fraction as centrifuge overflow; and feeding the centrifuge underflow into a second section of the hydrocyclone apparatus in which second section the starch is washed in counter-current with water and from which a concentrated washed starch fraction is delivered as underflow, whereby the separation of the pentosan-containing water fraction improves the yield of starch from the second section of the hydrocyclone apparatus.
4. Apparatus for use in separating wheat starch and gluten present in a pentosan-containing aqueous wheat flour slurry, said apparatus comprising a hydrocyclone battery incorporating a plurality of hydrocyclone stages, means for feeding said slurry and counter-current washing water into said battery to cause separation thereby of an overflow fraction containing gluten and some starch, characterised in that the hydrocyclone battery is divided into a first section for yielding an overflow fraction containing gluten and some starch, and a second section for yielding a washed starch fraction as underflow; a centrifuge is interposed between said first and second battery sections; means is provided for screening off agglomerated gluten from the overflow fraction of said first battery section, and there is means for feeding the remaining starch-containing part of that overflow fraction and also the underflow fraction from said first hydrocyclone battery section to said centrifuge to permit the latter to remove an amount of water together with pentosans as centrifuge overflow fraction, and means for feeding the centrifuge underflow fraction to said second section of the hydrocyclone battery.
5. Apparatus according to claim 4, wherein between said first hydrocyclone battery section and said centrifuge there is a fibre screening means for screening off fibre from at least part of the underflow fraction of said first battery section before that part enters said centrifuge.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8208768 | 1982-03-25 | ||
| GB8208768 | 1982-03-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1218360A true CA1218360A (en) | 1987-02-24 |
Family
ID=10529269
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000423962A Expired CA1218360A (en) | 1982-03-25 | 1983-03-18 | Separation of gluten and starch from wheat flour |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US4494530A (en) |
| EP (1) | EP0090533B1 (en) |
| JP (1) | JPS58170439A (en) |
| AT (1) | ATE20470T1 (en) |
| AU (1) | AU553545B2 (en) |
| CA (1) | CA1218360A (en) |
| DE (1) | DE3364138D1 (en) |
| FI (1) | FI72734C (en) |
| HU (1) | HU185823B (en) |
| PL (1) | PL134637B1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8510893D0 (en) * | 1985-04-30 | 1985-06-05 | Cpc International Inc | Starch separation process |
| DD258718A3 (en) * | 1985-10-30 | 1988-08-03 | Ve Kom Staerke Und Kartoffelve | METHOD FOR SIMULTANEOUS GAINING OF WHEATSTICK AND WHEAT GLUE |
| US5472511A (en) * | 1994-07-11 | 1995-12-05 | Board Of Trustees Operating Michigan State University | Method for the separation of proteins from grain flour |
| US5972119A (en) * | 1995-11-02 | 1999-10-26 | Flottweg Gmbh | Process and system for obtaining starch and proteins from the flour of legumes, in particular peas |
| US6045868A (en) * | 1999-01-06 | 2000-04-04 | Board Of Trustees Operating Michigan State University | Method for the preparation of transparent cross-linked polymers from grain flour |
| CA2432885C (en) * | 2000-12-22 | 2009-11-17 | The Horticulture And Food Research Institute Of New Zealand Limited | An improved procedure for separating starch from comminutates of plant materials |
| AU2002331469B2 (en) * | 2001-08-20 | 2008-04-24 | Cargill, Incorporated | Non-starch-polysaccharides |
| GB0718974D0 (en) | 2007-09-28 | 2007-11-07 | Univ Leuven Kath | oligosaccharides derived from arabinoxylan for prevention of gastrointestinal infection |
| GB0805360D0 (en) * | 2008-03-25 | 2008-04-30 | Univ Leuven Kath | Arabinoxylan oligosaccharide preparation |
| WO2010020639A1 (en) † | 2008-08-18 | 2010-02-25 | Bioactor Bvba | Arabinoxylans for modulating the barrier function of the intestinal surface |
| GB201110471D0 (en) * | 2011-06-21 | 2011-08-03 | Univ Manchester Metropolitan | Method and apparatus for the production of an arabinoxylan-enriched preparation and other co-products |
| JP6367794B2 (en) | 2012-05-23 | 2018-08-01 | カーギル インコーポレイテッド | Method for enhancing gluten and starch fractions in wheat flour |
| EP3313199A1 (en) | 2015-06-25 | 2018-05-02 | Manildra Milling Corporation | Gluten-free starch and methods of producing same |
| NL2015950B1 (en) | 2015-12-11 | 2017-07-03 | Borgesius Holding Bv | Flour blends and the use thereof in bread baking processes. |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2504962A (en) * | 1944-12-08 | 1950-04-25 | Us Agriculture | Separation of starch from wheat flour |
| US2488747A (en) * | 1946-08-10 | 1949-11-22 | Laval Separator Co De | Starch separation |
| US2773784A (en) * | 1952-04-04 | 1956-12-11 | Corn Prod Refining Co | Starch manufacturing process involving flotation and centrifugal separation |
| US2689810A (en) * | 1953-07-22 | 1954-09-21 | Stamicarbon | Separation of starch and gluten |
| US3901725A (en) * | 1971-09-15 | 1975-08-26 | Staley Mfg Co A E | Size classified cereal starch granules |
| US3951938A (en) * | 1972-09-08 | 1976-04-20 | Oy Vehna Ab | Method of separating gluten from wheat flour |
| FI48520C (en) * | 1972-09-08 | 1974-11-11 | Vehnae Ab Oy | Method for isolating gluten from wheat flour |
| FR2239524A1 (en) * | 1973-08-01 | 1975-02-28 | Staley Mfg Co A E | Large grain size cereal starches obtd. by hydrocyclone sepn. - used to replace arrowroot starch in carbon-free copying paper and anti-offset lithographic powder |
| US4280718A (en) * | 1975-03-24 | 1981-07-28 | Henkel Corporation | Pressure sensitive recording sheet containing size classified cereal starch granules |
| GB1596742A (en) * | 1976-08-24 | 1981-08-26 | Scholten Honig Research Nv | Method for the separation of wheat gluten and wheat starch |
| GB1561856A (en) * | 1977-01-24 | 1980-03-05 | Pfeifer & Langen | Method of preparing refined starch hydrolysates mainlyconsisting of monosaccharides disaccharides and higher saccharides from starch-containing cereals |
| AU527738B2 (en) * | 1978-05-24 | 1983-03-17 | Wessanen Nederland B.V. | Hydrocyclone cascade |
| GB2032245A (en) * | 1978-10-25 | 1980-05-08 | Barr & Murphy Int | Method of separating wheat gluten and starch from wheat flour |
-
1983
- 1983-03-11 EP EP83301357A patent/EP0090533B1/en not_active Expired
- 1983-03-11 AT AT83301357T patent/ATE20470T1/en not_active IP Right Cessation
- 1983-03-11 DE DE8383301357T patent/DE3364138D1/en not_active Expired
- 1983-03-15 US US06/475,507 patent/US4494530A/en not_active Expired - Fee Related
- 1983-03-18 JP JP58045827A patent/JPS58170439A/en active Pending
- 1983-03-18 CA CA000423962A patent/CA1218360A/en not_active Expired
- 1983-03-21 HU HU83932A patent/HU185823B/en not_active IP Right Cessation
- 1983-03-21 AU AU12650/83A patent/AU553545B2/en not_active Ceased
- 1983-03-21 PL PL1983241126A patent/PL134637B1/en unknown
- 1983-03-21 FI FI830937A patent/FI72734C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0090533A2 (en) | 1983-10-05 |
| EP0090533A3 (en) | 1984-01-18 |
| AU1265083A (en) | 1983-09-29 |
| HU185823B (en) | 1985-04-28 |
| EP0090533B1 (en) | 1986-06-18 |
| PL134637B1 (en) | 1985-08-31 |
| FI830937A0 (en) | 1983-03-21 |
| JPS58170439A (en) | 1983-10-07 |
| AU553545B2 (en) | 1986-07-17 |
| FI830937L (en) | 1983-09-26 |
| DE3364138D1 (en) | 1986-07-24 |
| ATE20470T1 (en) | 1986-07-15 |
| PL241126A1 (en) | 1984-06-18 |
| US4494530A (en) | 1985-01-22 |
| FI72734B (en) | 1987-03-31 |
| FI72734C (en) | 1987-07-10 |
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